Support of underground mining face is one of indispensable equipments in mining. The support equipment adopted in China includes various forms, such as wooden pillar, single frictional metal pillar, single hydraulic pillar, and dual-extension hydraulic pillar, etc. In recent years, owning to continuous research and practice effort of the engineers, the support technique gains significant development; the wooden pillar is rarely adopted; the single fractional metal pillar is also rarely used due to its poor and uniform setting load and uncertain constant increasing resistance lowering distance; the single hydraulic pillar is a new product developed after the single fractional metal pillar, and has been applied for more than 30 years. The single hydraulic pillar is provided with three-way valve, and hydraulic fluid supplied by emulsion station preset by working face is injected into oil cylinder of pillar via the three-way valve for initial support; when pressure is applied to the top plate and released, the emulsion is then discharged via the three-way valve, and the pillar is lowered; the hydraulic fluid from the emulsion station is reused in repeat work for initial support. The application of the single hydraulic pillar brings great convenience for the mining face, but issues as below still exist: 1) arc welding seam is provided on movable prop, which leads to lowered mechanical strength of the movable prop; when pressure is applied on the top plate, the welding seam is prone to fracture and crack, which is a potential safety hazard; 2) after wearing of the cylinder inner surface which is high pressure sealed surface, inner leakage of the pillar may occur, which is a potential safety hazard for mining workers; 3) the emulsion quality is not guaranteed due to poor underground water quality in coal mine, which leads to severe corrosion to the cylinder and the pillar failure; the quantity of failed pillars is about 300,000 each year, which is a dramatic waste. Now most coal mines adopt single hydraulic pillar, the demand for single hydraulic pillar is over 2,000,000 each year, therefore it is very important to further modify and improve the single support equipment.